The planned study is to improve the field's understanding of the cognitive and learning processes that shape two of the most chronic real world impairments seen in children with ADHD: social performance deficits and academic underachievement. Prior work has established that ADHD-related weaknesses in working memory (WM) directly impacts the ability of children with ADHD to explicitly acquire a cognitive skill, of which academic achievement would be but one example. Such work is relevant to a promising new direction in ADHD intervention which adopts a cognitive remediation approach to treatment. Initial findings from these cutting edge programs are encouraging; however, most target executive functions (EF) which are both poorly specified and non-unitary as individual constructs and as a collective group of processes. Results from the current application have the potential to answer the growing call to integrate neuroscience into educational and intervention programs by guiding the development of these programs through the identification of more specific/efficient cognitive target(s) for remediation. The first aim of the present study therefore asks whether slow speed of processing accounts for ADHD-related deficits in WM as well as the poor acquisition of explicit cognitive skills, which in turn would predict chronic academic underachievement. If this proves to be the case, then psychotherapeutic and pharmacologic interventions should target processing speed (as opposed to the more molar EF process), which would have positive downstream implications for a number of higher order executive processes, including but not limited to WM. Another potential rate limiting step to the development of innovative treatments, is that the examination of EFs has largely dominated research in the cognitive neuroscience of childhood ADHD, to the exclusion of other promising cognitive mechanisms. The second and third aims thus examine whether the implicit learning system, a learning system largely independent of EF, but dependent upon neuroanatomical structures implicated in ADHD (i.e. basal ganglia and striatum) and responsible for learning complex nonverbal rules used in directing social behavior, is (a) intact in children with ADHD, and (b) can predict social performance deficits in ADHD. Despite the availability of a number of empirically supported psychosocial treatments for ADHD, none have demonstrated long term benefits in the normalization of peer status or academic achievement. To meet these goals, we have adopted an SEM approach to systematically examine the potential conjoint contributions of EFs, speeded performance, and explicit/implicit learning processes on social and academic performance in children aged 8-12 with and without DSM-IV ADHD.The void in our basic understanding of skill acquisition processes in ADHD, combined with a need to improve our existing psychosocial and academic remediation programs, argues for a comprehensive study of explicit and implicit learning in ADHD, and of the cognitive processes that contribute to the acquisition of skill.